The present technology relates to a solid-state imaging device, a signal processing method thereof, and an electronic apparatus, and particularly to a solid-state imaging device, a signal processing method thereof, and an electronic apparatus, capable of suppressing a horizontal line or a vertical line caused by random noise.
Dark shading due to a dark current component of a pixel or an in-surface distribution of the dark current, and a horizontal line or a vertical line caused by the fluctuation of a reading circuit or a power supply occur in an image sensor. Here, the dark current is a current which is generated by electric charge accumulated in a photodiode even if light is not incident thereto.
Therefore, in the image sensor, a part of a pixel array section is blocked from light, and a pixel signal of a pixel which is blocked from light is detected to be produced as a clamp value. The clamp value is subtracted from a pixel signal of an effective pixel portion which is not blocked from light, thereby performing a clamp process for correcting dark shading, a horizontal line, and a vertical line (for example, refer to Japanese Unexamined Patent Application Publication No. 2004-15712).
However, random noise is included in the pixel signal of the light-blocked pixel, and thus there is a problem in that a random horizontal line or vertical line occurs due to the influence of the random noise.
In order to suppress the random horizontal line or vertical line due to the influence of the random noise, there is a method in which the number of light-blocked pixels for detecting a clamp value is increased, and an average value or a median value of the plurality of pixels is calculated so as to be used as a clamp value. However, if the number of light-blocked pixels is increased, a disadvantage of increasing a chip size occurs.
Therefore, a method has been proposed in which an average value or a median value of light-blocked pixels of a plurality of rows or a plurality of columns is used as a clamp value without increasing the number of light-blocked pixels, thereby suppressing a random horizontal line or vertical line (for example, refer to Japanese Unexamined Patent Application Publication No. 2006-157263).